Steering knuckle construction



March l?, 1953 R. c. HOFFMAN 2,631,855

STEERING KNUCKLE CONSTRUCTION Filed April 22, 1949 5 Sheets-Sheet l NM swg( v "i" 'fai "j" z i 3 T am frat/1157.5.

March 17, 1953 R, C, HOFFMAN 2,631,865

STEERING KNUCKLE CONSTRUCTION Filed Aprilv 22, 1949 5 sheets-sheet 2 JNVENTOR. Fao-cae C /a )9904/21 B Y A March 17, 1953 R. c. HOFFMAN STEERING KNUCKLE CONSTRUCTION 3 Sheets-Sheet 3 Filed April 22, 1949 I INVENTOR.

Patented Mar. 17, 1953 UNITED STATES PATENT ole-FICE- STEERING KNUCKLE CNSTRUCTION Roscoe C. Hoffman, etroit; Mich. Application April 22, 1949, Serial No.l 89,125

1 Claim. 1

This invention relates to steering knuckle constructions for the steerable wheels of vehicles such as automobiles. The principal object of the invention is to providev improved means for supporting steerable wheels with rel-ation to the upper an'd'lower control arms of an independent suspension system of the type having vertically spaced upperand lower suspension control arms.

Another important object of the present invention is'to provide such a steering knuckle and suspension structure which eliminates the need for akngpin and which combines the functions of the kingpin and steering knuckle means as commonly employed, and includes improved bearing means-connecting the outer` ends of the control arms tothe knuckle mea-ns in a manner efecting important simplification of design and reduction in the complexity and number of parts required, and' with a corresponding increase in the reliability, sturdiness and rigidity of the ass'embly.

Another object is to provide such an improved supporting structure forsteerable wheels having unique bearing means incorporating automatic take-up means adapted to prevent the development of unwanted bearing clearances and functioning also to cushion shock loads andl substantially lessen the transmissionfl of such loads from the wheels to the wheel suspension system and chassis frame and body of thevehicle.

A morejspecic-object is to provide such an improved Wheel supporting structure incorporatingA ball joints' of improved construction and also incorporating in each ball joint structure an internal rubber cushion so arranged as to provide bearing take-up and cushioningVY means as previousl'y indicated, the? parts being'v arranged in such manner'that in eventv of failure or deterioration of ther-rubber, the parts of the ballrjoint remain rigidly held and interlocked against unwanted separation.

Still another objectis to incorporate-in such a wheel supporting structure improved and simplied means foradjustment of the caster and camber angles.

Anotherl importantobject ofthe invention is to provide improved steerable supporting means for amotor vehicle wheel, which supporting. means is offthe type wherein the wheel is rigidly but detachably Secured-to a rotatable stub axle.

object relatedvto that last stated is to provide an improved composite steering knuckle `and front stub axle spindle support, including a equivalenti' massivel solid metal s-t1"u 'ture;VA carry- 2 ingrigidly secured thereto or integrated there` with; as by welding, atubular sheet metal bear# ing support for a rotatable wheel spindle of the character stated.

Ity is stillanother object of this inventionytoprovide such an improved steering knuckle structure adapted to be carried by ball and socket joint portions, incorporating novel and improved means for adjustment' of the .caster andcamber angles of the supported wheel,` and al1 .of theprim cip-al components of which maybe used` interchangeably upon the right or left side oi the vehic'le.

It is a further object of this inventionto` irrcorporate such improved steering knuckle struc; ture carried by ball andso'cket joint members, including ball parts which are cccentricallyk mounted in the controlearm'st of the suspensionv structure' and movable to different positionsl to effect caster and camber adjustments, one' such eccentric ball being so disposed that-adjustment thereof primarily alters the caster angle While the other, although similarly supported, is" mounted in-such position that adjustment there*- of primarily alters the camber angle.

4Still another object is to provide inconjunction'- with suchy ini-proved .ball and socket-type-steering knuckle Vsupporting means an improved dust Figure 1- isa very principally in diametric verf tical section, but'with partsr in elevationfshowing a wheel supporting structure constructed vinaccor'dance with the present-f'invention,y and illusf;

trating adj acentr portionsl ofthe supportedwheel and brake mechanisme Fig. 2 is an elevational view ofl thesteeringfv knuckle support removed4- from the remainder of the mechanism, takensubstantially as indicated by the line andarrows'Z-Z of Fig. 1;

Figs. 3 and L are sectional plan views substantiallyon thelines 3--3v and 4-4,' re'-A spectively, of Fig. l and lookinginl thedirectionv of the arrows Fig; 5v isa cross-sectionalrview of: a-resilient' cushioning liner.;4 d Fig. 6 is a sectionaly elevationalfview of a'modiedt-knuckle supporting-member;

Figs. 7 and 8" are cross-sectional views takenk substantially on thev linesV 1-'-1 and 8--,v respectively, ofFig; 6.y

ReferringA nowv to theV drawings;- reference.;

5r character lili'` designates the ylower control-.arm of an independent wheel suspension system which is illustrated as of the so-called Wishbone-type. Reference lcharacter I2 represents the upper control arm of the suspension system. These parts are shown only fragmentarily since the details of their construction and the mode of mounting and positioning of the arms form no part of my present invention and may be varied without departing from the invention. Suitable mechanisms of this character are familiar to those skilled in the art. As indicated, each control arm may include spaced upper and lower web portions. In the case of the lower lcontrol arm, aligned openings I4, I5 of like size are formed in the upper and lower webs, respectively, to constitute in effect a single orice which serves to locate a substantially circular split clamping block I6, having reduced circular upper and lower end portions as I8, tted in the openings I4, I5, respectively, and intermediate portions of greater diameter than such openings, las shown, so that the clamping block is trapped in position. A clamping bolt 22 extends transversely through the split end 24 of the block and, when tightened, rmly holds in position the substantially cylindrical hub portion 25 of the lower bearing ball 26, which ball may be formed integrally with the hub portion 25. The hub portion 25 is provided with a round-bottomed peripheral groove 23 through which the clamping bolt 22 extends so that the bolt serves as a key to positively lock the hub 25 against axial displacement. The groove 28 may be less than 360 in extent, to conne the angular adjusting movement of the hub within desired limits.

The ball 26 is positioned eccentrically with respect to the hub, being joined to the hub 25 by an integral stem portion 30. A drilled hole 32 for lubricant extends through the hubV portion 25, stem and ball 26, from the top of the hub portion 25, which is exposed above the control arm I0. The hole terminates at a lower portion of the surface of the ball remote from the stem. A portion 34 of the upper extremity of the lubricant passage 32 extends at an angle to the axis of the hub, and at its outer end such inclined portion is tapped to receive a lubricant fitting 31. When the lubricant tting is removed, any suitable tool such as a simple rod may be inserted in the inclined passage portion 34, and it will be understood that when the clamp-ing bolt 22 is loosened, the eccentrically positioned ball may be adjusted by rotating the same about the geometric axis I5 of the hub 25, simply by turning the hub with the aid of the rod. The movement of the ball during adjustment is in a circular orbit, an axis as |52 through the center of the ball and parallel to the axis I50 having translatory movement in a cylindrical path.

The upper control arm may also, like the lower arm, include spaced but rigidly connected upper andrlower web portions, such web portions of the upper arm being respectively designated 40, 42. The upper control arm I2 carries a ball 26a which may be supported in the arrn by supporting means substantially corresponding to the supporting means for the lower ball 26. The portions of the upper ball and supporting means corresponding to those of the lower ball and supporting means are designated by like reference characters distinguished by the addition of the letter a to each, and will require no detailed redescription. It will be observed, however, that the peripheral slot 28a, in the hub portion 25a which carries the upper ball is of greater angular length,.the slot 4 28a being so located that when the upper ball 26a is approximately in the mid portion with respect to its range of angular adjustment, a plane extended through the center of the ball and the axis of the hub portion 25a extends longitudinally of the car, so that rotation of the ball and hub through a limited arc about the axis of the hub moves the ball primarily in a direction transverse with respect to the car to eiect caster adjustment. On the other hand, the slot 28 in the lower ball hub 25 is so located that with the lower ball in its medial position of adjustment, a plane projected through the center of the ball and the axis of the hub extends transversely of the vehicle, so that the angular adjustment of the ball and hub in either direction from such medial position primarily effects movement of the ball toward the front or rear, thereby having its principal eiect in the adjustment of the caster angle.

A wheel-carrying knuckle support member 62 which may be forged of steel or otherwise suitably formed is provided with upwardly and downwardly extending arms 65, 61, respectively, which support socket portions in which the balls 26, 26a are received for swiveling movement. wardly extending arm 65 of the knuckle support is flared at its top to form the flange M and provided with a central recess 48 of spherical form. A pre-assembled bearing and cushioning structure is tted in the recess I8 and comprises a cupped sheet metal bearing shell 54 lined with babbitt or other suitable bearing alloy shaped to accurately receive the ball 26a and encircled by a cushioning -cup 52 of soft rubber or the like. The cup 52 is approximately semi-spherical' and is provided with a thickened rim portion 53 from which a flange 51 extends inwardly substantially radially. The relaxed diameter of the rim and flange portions 53, 51 is less than the diameter of the shell 54, and the cushioning cup is assembled upon the bearing shell by stretching the cushioning cup and its rim 53 and flange 51 so that the rim portion 53 encircles the bearing cup near the free edge of the latter, and the ange 51 extends inwardly across such free edge of the bearing cup. The tension then exerted by the thickened rim 53 and flange 51 is suflicient to hold the cushioning shell in place.

The -ange M is elongated toward the front and rear, as best shown in Fig. 2, so that the cupped ange assembly is substantially diamond-shaped, viewed in plan. A retaining ring 5-8 of corresponding peripheral contour iits over theY flange All, to which itis secured by cap screws 60. A bearing liner ring 59 is interposed between the retaining ring 58 and the ball .,216a,

the interior surface of the ring constituting in projects, so that a gap 63 is left extending en tirely around the base i'lange 6I, between such ange and the ring. The overhanging portion I1582 of the ring y58, also, does not project inwardly to engagement with the exterior of the shell `59. A similar annular gap is thereby formed between. By vir-v shell 59 and clamping ring portion 582. tue of this arrangement, the entire knuckle supporting structure can shift laterally with respect Y to the ball 26a, against the resistance of the rubber cushioning liner 52, under shock floadsf- It be appreciated that-thisincrea'ses the ei- The up- It will be noted that the diameter of Y s, fectiveness of cushioning of the interengaged metallic ball joint parts and materially reduces the tendency of Ysuch-parts togall one another. When thescrews 60 are tightened, the ring 58 draws the ring 59 downwardly against-the ball, urging the ball into the'bearingY shell 54l and thereby compressing the rubber liner A52 between the shell :54V andi socket 48; The-ange y6| also serves to retain and compress theiruhber liner, It will be understood that the minimum diameter of the ring I50 is less than the ball 26a, so that when the parts kare yassembled'.inthe.manner shown, the ball is securely. retained.

The downwardly projecting arm 61' of thel knuckle memberis turned outwardly to formthe apertured flange d5, andthe lower, ball. 216 pro-- jects downwardly through thev opening: |34 in ange 85. The lower' bearingisocketiportion for the bottomrball 26comprisesaafsheet metal bearing shell- 92 which may` be... faced. internally. with a suitable bearing metal of' babbitt: or other appropriate alloy as indicate at 493;. Acushioning liner 90 is similarly tted Vover*thesbearingshell and corresponds to. the previously described cushioning liner :52. may also be formed with lugdening forwardly and rearwardly extending portions :in which cap screws as 8'8 are adapted to befthreadedly fitted. The screws secure tothealower face of thearm portion '85 a` supportingsocket member 64v in which the bearing4 shell and cushioning liner.y

elements .52, Quaiareztted. These. parts. are-likewise. so proportoned that. when the screws 88 are tightened, the cushioningv liner 911 is compressed andthe bottom bearing shell section 92 is urged upwardly against the bottom of the ball to compress the ball between bearing shell portions-9.2., 113,0-,

The lubricant passage (notshown) for the upper ball isY alsovformedA with an inclined upper end portion for the reception ofl a rod or other tool when its lubricant fitting. 31a is removed. Alsoin corresponding fashion, the clamping bolt 22a mayA extendthrough .a round-bottomed peripheral groove 28a..in the hub; 25a so that the clamping bolt locks the. ballagainst displacement, although the grooverpermits rotation of the ball and its. hub.. when.. the bolt is loosened?.

The socket bearing portion carried by the lower out-fturnedarm portion1815 of the. steering knuckle. element. 62. may-include, a.: separateannular shell 130. slfrapedv to; conf-Vorm to the ball and having a base flange |32 retained in a counterbored portion 1| 33 formed in the bottom of" the arm B5. The opening |i3f4in the armportion 85 is substantially larger than the external diameter of the shell. An annular space is thereby defined between the shell and arm which is so proportioned as to receive the lower margin of a exible protective sleeve |35. The sleeve may be formed of synthetic rubber or the like and is provided with an enlarged bottom bead or rim portion |130 which is retained in the annular opening referred to, such opening being somewhat enlarged at its lower portion directly above the iiange y|312 to receive and retain the bead |36. The lower portion of the protective sleeve |35 is also compressed between the bearing ring |30 and the arm 85, so that the sleeve is tightly gripped and effectively sealed at its lower end. At its upper end, the sleeve is provided with a thickened bead portion |38, the relaxed diameter of which is less than the relaxed diameter of the stem portion 30 against which it bears when the sleeve is installed in The. lowerarm portion 8'5.A

bearing against a peripheral portion of the stub reception of. the bearing nut IIE).

6. the manner shown inFig. 1. The sleeve is sumciently resilient so rthat the portion |30 maybe stretched to pass over the hub 25 orv over the ball 26 during installation of the sleeve. It will be observed that the counterbored portion |33 is also of greater diameter than the base ilange |132 of bearing. shell portion |30, so that lateral movement of the parts carried by. the knuckle structure can occurwith respect to the ball and bearing shell portions against the resistance of the precompressed rubber cushioning liner 00. The action of these parts is analogous tothose of the upper joint portions previously. described.'

An upper protectivelubricant retaining sleeve |40. isalso provided. As shown in the drawing,`

the lower end of the upper sleeve may be provided with a conventional thickened rim portion |f42 adapted to encircle and bear tightly inward ly against the socket; backing andy supporting' portion 4d formed at the upper` end of the knuckle arm 6.5.

|40 is formed with asimilar stretched rim or bead portion |44 which embraces the stem 30a.

The knuckle support member 62 is provided with a. cylindrical hub flange portion adapted to. carry the wheel bearing supporting knuckle.

sleeve. 96, which may be welded. to the oppositev ends, of the. knuckle hub ange- 95, as indicated at 98., 00.

A stub axle` |00 is journaled in the knuckle sleeve 9S as in suitable antifriction bearings |02, |04.

At its outer end, the stub axle IDB may be hot upset or yotherwise provided with a head adapted to form. an integral flange |05 dening a wheel supporting hub to whi-ch a disk wheel |06 may be secured as by the screw means |08.

The inner end of the knuckle tube 96 is. open inside knuckle support member B2 and the stubI axle |00 is tapered to reduced diameter and projects inwardly to an accessible position; inside knuckle member 62, where itis threaded for 2 is fitted in the end of the. knuckle tubeSS to-enclose the inner end'of thestructure, the'outer end ofi .which is sealed by a suitable grease retainer as ||4 carried by the knuckle tubeand axle. A shoulder` ||5 serves as an abutment for the cone of the outer wheel bearing assembly |04. The cup of this bearing assembly |04 is located by an integral shoulder H6 rolled or otherwise suitably formed in the knuckle tube S6. The cup portion of the inner bearing assembly |02 is located by a plurality of lug-defining shoulders as |`|8, pressed inwardly and partly sheared from the wall of the tube 06, tbe cone of the bearing |02 being retained by a washer |20 beneath the nut ||0.

The knuckle support member 62 may be provided with conventional integral pierced lug portions |22 through which bolts (not shown) may extend to carry the brake support and backing plate |25 and the steering arm |24.

It will be appreciated that the parts may be so proportioned and initially adjusted that the wheel is approximately at the proper caster angle when The upper end of the sleeve A grease capthe ball 26 is' near the outer limit of its adjustment, as shown in the drawings, and that relatively slight rotary movement f the hub 25 moves Athe ball toward the front or rear of the vehicle to a greater extent than the ball 26 is moved inwardly or outwardly toward the center line of the car. The normal intended range of adjustment of the ball is less than 90, so that the principal adjustment eiected by moving the ball 26 through such range is one of caster, although the camber angle is of course also affected to a slight degree. The parts are also so proportioned that the camber angle of the wheel iS in the neighborhood of the desired value when the upper ball 26a is near the front or rear limit of its range of adjustment, and the normal range of adjustment is less than 90 so that adjustment of the position of the upper ball affects principally the camber angle. It will be understood that any undesired camber adjusting effect of the movement of the lower ball may be counteracted by readjusting the upper ball and, conversely, the caster effect resulting from adjustment of the upper ball can be counteracted by readjustment of the lower ball.

The relaxed conguration of the resilient cushioning liners may be substantially as shown in Figure 5, and it will be appreciated that the liner may be stretched over the ball, in each case, and then compressed when the parts are drawn together by the screws 60 or 8S.

As wheel suspensions of the type under consideration are commonly constructed, the lower control arm carries substantially the entire load and transmits it to the chassis frame through a coil compression spring (not shown). The lower ball and socket portions may accordingly be of greater diameter than the upper ball and socket portions which are only required to carry a relatively small proportion of the weight of the vehicle resulting from the resolution of forces.

In Figs. 6, 7 and 8, I have shown a modified steering knuckle supporting assembly 62a adapted to be integrally constructed as a one-piece forging, wherein the upwardly and downwardly extending arms 65a, 67a, respectively, are integral with al tubular bearing supporting section 69a which includes two necks, 95a, 95a.. Neck 96a projects outwardly to support the outer wheel bearing cup portion [04a and neck 95a projects inwardly to support the bearing cup |02a of the inner wheel supporting bearing assembly.

Relieved areas in the form of radially enlarged notched portions I32a, 134m are formed in the inner walls of the neck portions 95a, 96a behind the seats for the bearing cups |02a, loda, so thatv when it is desired to remove such bearing cups, suitably hooked pulling tools or the like may be engaged behind the same to allow the cups to be pulled out. i

Other parts of the modified unitary construction of Figs. 6-8 will be seen to correspond to those of the previously described construction and to require no detailed redescription.

While it will Vbe apparent that the preferred embodiments of the invention herein disclosed are well calculated to fulll the objects above stated, it will be appreciated that the invention is susceptible to modication, variation and ychange without departing from the proper scope or fair meaning of the subjoined claim.

YWhat is claimed is:

A steering knuckle construction comprising a double-armed forging having an intermediate i11- tegral hollow hub portion, a knuckle tube welded in and projecting from the hub portion and adapted to serve as a wheel bearing support, the tube being formed of sheet metal and exteriorly welded'to said hub portion and a portion of the tube within the hub being deformed inwardly to provide internal bearing locating shoulder means, and an outwardly deformed portion integral with a part of said tube'outside the hub dening a substantially cylindrical enlargement adapted t0 receive a wheel bearing and also defining a shoulder adjoining the enlargement for locating such bearing, said rst-mentioned shoulder means and last-mentioned shoulder facing outwardly in opposite directions.

ROSCOE C. HOFFMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,706,556 V/'right Mar. 26, 1929 2,069,253 Kliesrath Feb. 2, 1937 2,160,271 Kliesrath f May 30, 1939 2,162,828 Slack June 30, 1939 2,257,557 Webb et al Sept. 30, 1941 2,405,458 Slack et al. Aug. 6, 1946 2,426,358 Klages et al. Aug. 26, 1947 2,435,814 Allison Feb. 10, 1948 2,455,343 Slack et a1 Nov. 30, 1948 FOREIGN PATENTS Number Country w Date 603,199 Great Britain June 10, 1948 

